Yangshuo, Guilin and Longji are famous for there beautiful scenery in China and around the world. Guilin is, especially among Chinese tourists, known for its famous city parks, whereas Yangshuo and Longji are known for there countryside scenery.
The Li river (Li jiang) runs downstream from Guilin to Yangshuo (70km). The part between Yangdi and Xingping is considered the most beautiful part with the most spectacular karst mountain formations.
Maybe for this reason a viewpoint near Xingping is depicted on the 20 RMB Chinese banknote. Downstream from Yangshuo, on the more quiet part of the Li river, are the old villages of Fuli and Liugong, with farmer markets and old temples.
This is also the part where kayaking is possible. Li river is/was also the place of the famous cormorant fisherman. Nowadays this is down for tourists in the evening.
The smaller Yulong river runs a bit to the southwest of Yangshuo and enters the Li river below Yangshuo. The karst peaks around the Yulong river are also very scenic and is a popular place for bamboo rafting near the 500 year old Yulong (dragon) bridge.
The whole area around Yangshuo, the Li river and the Yulong river is dotted with small farm and fishing villages which can be explored with mountain and/or motorbikes. These countryside tours are usually combined with a visit to the famous Moon hill and a countryside food lunch.
In Yangshuo itself many activities can be done, like Chinese cooking class, calligraphy, Kung Fu, Tai Qi lesson(s). In the evening many people want to visit the spectacular Liu Sanjie Lights show directed by Zhang Yimou, the person who created the 2008 Olympic opening show. The show involves around 500 actors.